Living in a home with others causes you to get comfortable with them, to get complacent, and to get lazy. One example of this is when you need something from someone else.
If they aren’t in the same room, it’s easier to scream for them than to get up and address them properly. This, of course, starts a pattern and before long everyone in the house is doing it and the ones on the receiving end will grow more and more annoyed with it.
One problem with this is when the unthinkable happens, and you need someone immediately. Having someone run to you instantly might be the difference between life and death. Seconds matters. By training others in your house that your screams aren’t important, on that day you need them, they just might ignore you.